/*  
 * Copyright 2008 CoreMedia AG, Hamburg
 *
 * Licensed under the Apache License, Version 2.0 (the License); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at 
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an AS IS BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License. 
 */

package com.coremedia.iso.boxes;

import com.coremedia.iso.IsoTypeReader;
import com.coremedia.iso.IsoTypeWriter;
import com.googlecode.mp4parser.AbstractFullBox;

import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import static com.googlecode.mp4parser.util.CastUtils.l2i;

/**
 * Samples within the media data are grouped into chunks. Chunks can be of different sizes, and the
 * samples within a chunk can have different sizes. This table can be used to find the chunk that
 * contains a sample, its position, and the associated sample description. Defined in ISO/IEC
 * 14496-12.
 */
public class SampleToChunkBox extends AbstractFullBox {
  List<Entry> entries = Collections.emptyList();

  public static final String TYPE = "stsc";

  public SampleToChunkBox() {
    super(TYPE);
  }

  public List<Entry> getEntries() {
    return entries;
  }

  public void setEntries(List<Entry> entries) {
    this.entries = entries;
  }

  protected long getContentSize() {
    return entries.size() * 12 + 8;
  }

  @Override
  public void _parseDetails(ByteBuffer content) {
    parseVersionAndFlags(content);

    int entryCount = l2i(IsoTypeReader.readUInt32(content));
    entries = new ArrayList<Entry>(entryCount);
    for (int i = 0; i < entryCount; i++) {
      entries.add(new Entry(
          IsoTypeReader.readUInt32(content),
          IsoTypeReader.readUInt32(content),
          IsoTypeReader.readUInt32(content)));
    }
  }

  @Override
  protected void getContent(ByteBuffer byteBuffer) {
    writeVersionAndFlags(byteBuffer);
    IsoTypeWriter.writeUInt32(byteBuffer, entries.size());
    for (Entry entry : entries) {
      IsoTypeWriter.writeUInt32(byteBuffer, entry.getFirstChunk());
      IsoTypeWriter.writeUInt32(byteBuffer, entry.getSamplesPerChunk());
      IsoTypeWriter.writeUInt32(byteBuffer, entry.getSampleDescriptionIndex());
    }
  }

  public String toString() {
    return "SampleToChunkBox[entryCount=" + entries.size() + "]";
  }

  /**
   * Decompresses the list of entries and returns the number of samples per chunk for every single
   * chunk.
   *
   * @param chunkCount overall number of chunks
   * @return number of samples per chunk
   */
  public long[] blowup(int chunkCount) {
    long[] numberOfSamples = new long[chunkCount];
    int j = 0;
    List<SampleToChunkBox.Entry> sampleToChunkEntries = new LinkedList<Entry>(entries);
    Collections.reverse(sampleToChunkEntries);
    Iterator<Entry> iterator = sampleToChunkEntries.iterator();
    SampleToChunkBox.Entry currentEntry = iterator.next();

    for (int i = numberOfSamples.length; i > 1; i--) {
      numberOfSamples[i - 1] = currentEntry.getSamplesPerChunk();
      if (i == currentEntry.getFirstChunk()) {
        currentEntry = iterator.next();
      }
    }
    numberOfSamples[0] = currentEntry.getSamplesPerChunk();
    return numberOfSamples;
  }

  public static class Entry {
    long firstChunk;
    long samplesPerChunk;
    long sampleDescriptionIndex;

    public Entry(long firstChunk, long samplesPerChunk, long sampleDescriptionIndex) {
      this.firstChunk = firstChunk;
      this.samplesPerChunk = samplesPerChunk;
      this.sampleDescriptionIndex = sampleDescriptionIndex;
    }

    public long getFirstChunk() {
      return firstChunk;
    }

    public void setFirstChunk(long firstChunk) {
      this.firstChunk = firstChunk;
    }

    public long getSamplesPerChunk() {
      return samplesPerChunk;
    }

    public void setSamplesPerChunk(long samplesPerChunk) {
      this.samplesPerChunk = samplesPerChunk;
    }

    public long getSampleDescriptionIndex() {
      return sampleDescriptionIndex;
    }

    public void setSampleDescriptionIndex(long sampleDescriptionIndex) {
      this.sampleDescriptionIndex = sampleDescriptionIndex;
    }

    @Override
    public String toString() {
      return "Entry{" +
          "firstChunk=" + firstChunk +
          ", samplesPerChunk=" + samplesPerChunk +
          ", sampleDescriptionIndex=" + sampleDescriptionIndex +
          '}';
    }
  }
}
